Nestable culvert



Patented May 18, 1926.

iran vsrarEs 1584s@ s r I c PATENI KARL JOHAN vTIIoRsBY,'or'oAKLANn CALIFORNIA, AssIGNoR To CALIFORNIA coa- RUGATED CULVERT'COMPANY, 0F OAKLAND, CALIFORNIA, A CORPORATION OF CALIFORNIA.

' NESTABLE CULVERT.

Application filed February 18, 1925. SeralNo. 9,967'.

". vert is equipped with joint-forming tongues along its side edges, alternate tongues being offset, the others remaining in the arc of curvature.

Heretofore, it has been customary to make said alternating ofi'set and non-offset tongues by means of slits or cuts directedat right angles to the longitudinal axis of the section, resulting in the tonguesbeing rectangular.

TWhen, therefore, the sections are nested into bundles, the parallel sided tongues, due

to the interference of the sides of the offset tongues of one section with the sides of the non-olfset tongues of the adjacent section, cause the innermost sections of the bundle to compress and decrease in diameter, while the outermost sections spread and increase in diameter, thus making it not only ditiicult to assemble them, but also preventing them from nesting with minimum closeness. This want of closeness inthe nesting is serious for two reasons, namely for economical CPI transportation and for handling. For shipping purposes, it is essential that each bundle should comprise enough sections' to produce the required volume weight equivalent. In the larger sizes of culverts, the number of sections in each bundle is comparatively large and, therefore of great weight.

Again, a large market for nestable culverts is in countries where the bundles are handled by coolies. Tt is, therefore, of importance that the bundles contain as few sections as possible in order to make their handling easy.

The object of my invention is to meet the above requirements as well as to reduce the objections to a minimum.

To these ends my invention consists in the novel nestable culvert-sections hereinafter fully described by reference to the accompanying drawings, in which Fig. l is a perspective view of a nested bundle of my improved culvert-sections.

Fig. 2 is a fragmental side elevation of two nested sections, the flaring offset tongue of the outer section being cut away to show the clearance of the corresponding tongue of the under section.

Fig. 3 is a section on the line 3-3 of Fig. 2. l

It will be understood that the culvert-sections here shown are half sections only of a 'complete culvert, the other half sections, which are merely complemental and have straight edges that is, 'without tongues, present no problem of close nesting and, there-y fore, need not be herein illustrated since the nesting problem only concerns and is due to the alternating offset and non-offset tongues of the sections here shown.

In the drawings, the nume al l indicates the arcuate culvert-sections under present consideration. The side edges of each section are provided with tongues formed by slits or cuts extending inwardly from said edges. Alternate tongues indicated by Q are odset from the general arc of the section while the remaining tongues indicated by 3 are not offset but are left in the normal arc of curvature.

Heretofore, the slits or cuts which form these two kinds of tongues have been parallel with each other and extend at right angles to t-he longitudinal axis of the section. The tongues, therefore, have been rectangular with straight parallel sides, and because of the interference of the sides of the offset tongues of one section with the sides of the non-offset tongues of the adjacent section, it is impossible to nest the sections to a close lit without considerable distortion. In other words the offset tongues of each section catch on the non-offset tongues of the outlying or overlying section, resulting in the spreading of the sections, leaving an air space between them, and this produces a larger bundle, thus requiring more sections in order to obtain the needed weight.

In accordance with my present improvement instead of making the tonguedetining slits or cuts parallel with each other and at right angles to the axis of the section as has been the previous custom, I make said slits or cuts, designated by 4 in planes successively oppositely inclined to the axis of the section. This results in making two shapes of tongues, one shape flaring to its extremity and the other shape tapering to its extremity, and these shapes alternate as shown. Those tongues which iare outwardly, and to which the term dovetailed may be applied are offset from the normal arc of the section, and they are the tongues designated by 2. The other tongues 3 are not offset but remain in the normal arc of curvature.

Now when, as shown in Figs. l and 3, one section is litted over and down upon another section it will, to the extent of its thickness, have its side edges raised higher than the side edge ot the underlying section, and this will present its vacancies or spaces from which its dovetailed tongues have been oil"- set, in a correspondingly higher plane than the oliset tongues o'l` the underlying section, enabling' said underlying oliset. dovetailed tongues to freely enter said vacancies without interference vith the side edges ot' the overlying tapered tongues 3. In other words. on account ot the opposite inclination ot the cuts il, the radial displacement ot two adjacent nested sections will provide a clearance between the edges of each ol'lisety dovetailed or 'flaring tongue 2 ot the under section and the adjacent edges otl the two tapered tongues 3 ot' the outer section between which said otf'set dovetailed sections lies, as shown at 5 in Fig. 2.

I claim l. Arcuate culvert sections having sides wit-h terminal edges, said sides being provided along their edges with a succession of tongues, alternate tongues having sides converging from extremity to base and the intervening tongues having sides converging from base to extremity, said first named tongues being bent at their bases to ol'set them trom the normal arc ot' the culvert section, and said last named tongues lying in said are.

2. Arcuate culvert sections having sides with terminal edges, said sides having slits leading from their edges in planes successively oppositely inclined to the longitudinal axis of the section, forming along the sides a succession otl tongues, alternate tongues having sides converging from extremity to base and the intervening tongues having sides converging from hase to extremity, said first named tongues heilig bent at their bases to offset them from the normal are ol the culvert section, and said last named tongues lying in said arc.

In testimony whereof I have signed my name to this specification.

KARL JOHAN THORSBY. 

